<template>
  <div>
    <div>{{ teacher.name }}</div>
    <div>{{ teacher.age }}</div>
    <div>{{ teacher.salary }}</div>
    <button @click="timeFly">过了一年</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      teacher: {
        name: 'harry',
        age: 28,
        salary: 3000,
      },
    }
  },
  methods: {
    timeFly() {
      this.teacher.age += 1
      this.teacher.salary += 500
    },
  },
  watch: {
    'teacher.age'(value, oldvalue) {
      this.teacher.age > 40 ? alert('老师年龄到了，该退休了') : ''
      console.log('我以前的工资是' + oldvalue, '我现在的工资是' + value)
    },
  },
}
</script>

<style></style>
